docs: def txn_storeAssociation(self, server_url, association):
          """Set the association for the server URL.
  
          Association -> NoneType
          """
          a = association
          self.db_set_assoc(
              server_url,
              a.handle,
              self.blobEncode(a.secret),
              a.issued,
              a.lifetime,
              a.assoc_type)